I am on step of leaving work for good

I work for my dad small business and he called me screaming about the electric door gate and that I ruined it . We had a customer picking up some counters because we do marble fabrication . But any way I tried telling him what happened and he told me I keep things from him and I suck as a employee . He went off to call my sister and she called me screaming about it too . I am 22 weeks pregnant and I went off on her since she told me my husband is with out work so he has been helping him and I work for him he states to her that he did not want me to go in on Monday but I plan to leave for good I can't handle the stress my sister uses me as her nany she has a daughter and is always asking for help I always end up cleaning the floor even after I asked her to help but she won't .